Using Linq to filter an array with bool properties true in to another array

Question

I have an array of type Brick with each brick having an isBroken bool property. How can I use Linq to filter all bricks with isBroken = true into a new array?

Answer 1

Use Where to filter the list of bricks and ToArray to materialize the result into a new array.

var result = MyBricksArray.Where(x => x.isBroken).ToArray();

Answer 2

I hope this example will explain things more clearly, Let the definition of your class will be like the following:

public class Brick
{
  public string Name;
  public bool isBroken ;
}

And the Array of it's objects is defined like this:

Brick[] BrickArray =new Brick[]{
                    new Brick(){Name="A",isBroken=true},
                    new Brick(){Name="B",isBroken=true},
                    new Brick(){Name="C",isBroken=false}};

Then you can use the .Where to filter the collection like the following:

var selectedBriks = BrickArray.Where(x=>x.isBroken).ToList();

Now the selectedBriks will contains the items with name A and B

Answer 3

You can use the select method for this :

var theNewList = Brick.Where(b => b.isBroken).Select(b => new Brick
{
    //Populate new object
}).ToList() / .ToArray(); 

Note that Select is used and not where to project the List into a new one.

Also, the .ToList()/ToArray() is to add the array to memory, you may not need it, .Select() return an IEnumerable. It is possible to use Brik.Where(..).ToList(); as this would create a new List but the reference to the object inside the list would be the same, so again it depands on your need. And .Select() require using System.Linq;